Dandruff problems affect up to 50% of the world's population. They affect both men and women and are perceived as having a very negative psychosocial impact. The appearance of dandruff is bothersome both aesthetically and because of the trouble it causes (itching, redness, etc.), and as such many people confronted with this problem to variable degrees wish to eliminate it efficiently and permanently.
Dandruff corresponds to an excessive and visible desquamation of the scalp resulting from the excessively rapid multiplication of the epidermal cells and from their abnormal maturation. This phenomenon may be caused in particular by microtraumas of physical or chemical nature, such as excessively aggressive hair treatments, extreme climatic conditions, nervousness, diet, fatigue and pollution, but it has been demonstrated that dandruff conditions usually result from a disorder of the microflora of the scalp and are more particularly due to the excessive colonization of a fungus belonging to the family of yeasts of the Malassezia genus (previously known as Pityrosporum ovale) and which is naturally present on the scalp.
Many antidandruff treatments have been developed with the main objective of eradicating Malassezia yeasts from the scalp. Thus, the activity of the major antidandruff active agents of today, such as zinc pyrithione, piroctone olamine or selenium disulfide, is based mainly on their fungicidal property. However, these antidandruff agents are not completely satisfactory in terms of effectiveness (immediate effectiveness or duration of the effect) and/or in terms of impact on the environment.